s = '123af d 56'
def only_s(s):
    # 判断字符串中的字符是否唯一，是（true), 否（false)   注：空格不算入字符
    s = list(s)
    s.remove(' ')
    i = 0
    while 1:
        num = len(s)
        if num == 1:
            return True

        for q in range(1, num):
            if s[i] != s[q]:
                pass

            else:
                return False

            if q == num-1:
                del s[i]


# 方法2
def func(str):
    for i in range(len(str)):
        if str[i] in str[i+1:]:
            return False
    return True


print(func(s))
print(only_s(s))